Behavioral -- Iterator

--- Iterator.java ---

package behavioral.iterator;

public interface Iterator {

Object currentItem();

boolean isDone();

Object next();

Object first();
}

--- ConcreteIterator.java ---

package behavioral.iterator;

public class ConcreteIterator implements Iterator {

private ConcreteAggregate theAggregate;

public ConcreteIterator(ConcreteAggregate aggregate) {
theAggregate = aggregate;
}

public Object next() {
return null;
}

public boolean isDone() {
return false;
}

public Object first() {
return null;
}

public Object currentItem() {
return null;
}

}

--- Aggregate.java ---

package behavioral.iterator;

public interface Aggregate {

Iterator iterator();

}

--- ConcreteAggregate.java ---

package behavioral.iterator;

public class ConcreteAggregate implements Aggregate {

public Iterator iterator() {
return new behavioral.iterator.ConcreteIterator(this);
}

}